Am looking to edit system preferences settings via the command line but cannot for the life of me find the correct names of variables.

In Login Options under Users & Groups, I would like to be able to change the Display login window from list of users to 'name and password'.
In Date & Time, I would like to know how I change the time to a server we use.
Enable fields in Sharing
Setup Energy Saver settings

It would be great if someone can help me out or point me in the right direction as I know you edit the preferences .plists but its knowing what to add or finding the preferred naming conventions.

Launch System Preferences.
Make a change via the GUI.
Probably best to do one change at a time,
e.g. I changed "Display Login Window as:"
from "List of users"
to "Name and password".
Quit System Preferences.